/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/NiagaraParameterDefinitionsSubscriberViewModel.h
Find a subscribed Parameter Definitions with a matching Id GUID, or otherwise return nullptr.
[UNiagaraParameterDefinitions](API\Plugins\NiagaraEditor\UNiagaraParameterDefinitions) * FindSubscribedParameterDefinitionsById ( const [FGuid](API\Runtime\Core\Misc\FGuid) & LibraryId )